Benefits of multiple links from same site

I am about to sponsor a site which has a PR7 home page. Most content pages are PR5-6.

My text links will be full run of site and I am expecting several hundred (possibly over 1000) back links to be produced as a result.

The site I am sponsoring is highly indexed in Google so I know that backlinks from it are valid in Google terms.

My question is, how effective will these backlinks be since they are all from one site?

As you can appreciate, the cost is significant, so I am trying to analyse the effectiveness of such a campaign first.

I would appreciate any insight.

Thanks.

you will benefit greatly since so many pr6 pointing to your site, however whether you can gain #1 depends on how competitive the keyword is, if the #1 already have Pr 8, it still seems not easy. And no one can guarantee you are the number one, so you have to try it for maybe several months and see if it works.

The keyword is ULTRA competitive.

I know I wont rank number 1. Im just hoping for top 30. However, I'm looking for further site sponsorship's in order to increase exposure further, so with two or three of these running, and several thousand PR5,6, or 7 backlinks, I could do rather well.

Time will tell I suppose. Thanks for responding.